Support

FAQs for Abnormal Noise from DC Fan
Applicable Equipment Models: HTX 06–20KVA

Q: The DC fan inside the UPS I purchased from your company has recently started making abnormal noise. What is the reason?
A: The main causes are either the fan speed level has been set to Level 2 via the MTR software, or one or more DC fans inside the UPS have malfunctioned.

Q: However, there is no fan fault alarm code displayed on the UPS. How can this be explained?
A: In some cases, the "Fan Fault" alarm has been disabled via the MTR software, which is why the code is not shown.

Q: How can I resolve the fan abnormal noise issue?
A: Please follow the solutions below:
1.Connect to the UPS using MTR software and configure the parameters as follows:
1）Path 1: ServSetting → System Setting → 3-level Fan Speed Control → Select Enable
Note: If set to Disable, fan speed will increase significantly, resulting in louder noise.
2）Path 2: Rated Setting → System Code Setting 1 → Check FanFailBzOnEn → Restart the equipment.
After rebooting, check if fault code 53 (fan fault code) appears on the UPS screen.
Note: If a fan fault or code 53 occurs, the fan will run at maximum speed, causing increased noise.

Summary:If 3-level fan speed is enabled and fan fault alarm is checked, the fan will operate at the lowest speed level and noise under normal working conditions.

Switch to English by opening the software in administrator mode. If this does not resolve the issue, please contact the INVT engineer. Email address: support@invt.com.cn   

Add New relay function P06.00~P06.21 = 92: MV switch-on allowed
+ Operational logic:
IF (Control power on = true) 
AND (VFD fault = false)
AND (Emergency stop button off = true)
THEN
    Relay output := 1;
ELSE
    Relay output := 0;
In  MVD ARM Software V3.08, a feature has been added that allows the system to automatically issue a closing command.  

Troubleshooting steps:

1 This fault occurs during the EEV pressure equalization phase. When this alarm appears, the EEV cannot complete initialization, and the unit cannot enter cooling or dehumidification mode.

2. When this alarm occurs, first check the suction pressure and discharge pressure values in the sensor status. Based on the refrigerant type and current temperature, consult the corresponding saturation pressure-temperature chart to verify whether the pressures are too high or too low.

3. Check whether all valves in the unit are fully opened, including solenoid valves, check valves, ball valves, and indoor/outdoor unit service valves. Remove the pressure sensors and inspect them for oil blockage; clean them if necessary.

4. Connect a pressure gauge and compare its readings with the values displayed on the controller. If there is a significant deviation, it is likely that the pressure sensor is faulty. If other alarms are present at the same time, contact the manufacturer for further assistance.

Troubleshooting steps:

1. In the status menu, go to Equipment Status – Humidifier Runtime and check the actual humidifier runtime.

2. If the actual runtime exceeds 2000 hours (default value), the humidifier requires cleaning and maintenance. After maintenance is completed, log in with the service password 504600, locate the time reset option, and clear the humidifier runtime. Then, confirm in the status menu that the humidifier runtime has been reset to zero, and manually clear the alarm.

3. If the actual runtime is less than 2000 hours (default value), the cause may be a protocol error, outdated software version, or an alarm threshold set too low. In this case, provide the software version number and serial number (SN) and contact the manufacturer for assistance.

FAQ For INV IGBT Driver Block-Set Alarm
Applicable Equipment Model：RMX 40/50X

Q: The equipment suddenly reports an "INV IGBT Driver Block-Set" fault. What is the cause?
A: The main cause is abnormal inverter voltage or abnormal voltage detection.

Q: How should we troubleshoot and resolve this fault?
A: Please follow the inspection steps below:
1. Check the inverter power board
* Inspect the inverter power board of the power module for obvious burn marks.
* Check whether key components (such as inverter driver / inverter IGBT) are damaged.
Recommendation: If a spare inverter power board is available, power off the equipment first, replace the board, then restart the unit to check if the alarm is cleared.
2. Check the inverter busbar board
* Inspect the inverter busbar board for obvious damage.
* Check whether the fuse on the inverter busbar board is blown.
Recommendation: If a spare inverter busbar board is available, power off the equipment first, replace the board, then restart the unit to check if the alarm is cleared.

This is the test mode for the keyboard control board. Pressing “PRG” and “ENT” simultaneously activates it. It is a method we use during debugging to verify whether the control board is functioning properly. Simply power cycle the device to exit test mode.

1. manual bypass, set P13.11 manually to bypass the corresponding unit group 
2. automatic bypass, when the VFD unit fails, the VFD automatically bypasses the corresponding unit group 
3. neutral point bypass, when a unit fails, the VFD automatically fails the unit 
Caution, 
1. bypass up to 2 groups of units 
2. when the unit communication fails, the unit can not receive bypass commands and can not be bypassed 
3. after neutral point bypass, you need to set P13.10 = 0, and then set P13.11 to reset the unit bypass status. Cannot be bypassed 3. After neutral point bypass, you need to set P13.10=0 and then set P13.11 to reset the unit bypass status.

Q: When the GD200A inverter is connected to a motor, the operating frequency does not rise above 19 Hz and a low-voltage fault is reported. However, it operates normally without a motor connected. What are the possible causes?
A: Causes:
1. The input voltage—especially during startup and when reaching 19 Hz—is below 340 V (for a three-phase 380 V inverter). This could be due to worn-out contactor contacts or poor contact in the upstream circuit breaker/fuse;
2. The internal electrolytic capacitors in the inverter may degrade over time or in high-temperature environments, resulting in reduced energy storage capacity;
3. There may be insulation issues with the motor or cables.
Troubleshooting Steps:
1. First, use a multimeter to measure the input voltage and check if it drops significantly when the motor reaches 19 Hz. If so, address the external wiring.
2. If the input voltage remains stable, the issue is most likely due to aging capacitors inside the inverter or a problem with the rectifier circuit’s contactor. Replace the contactor or capacitors.